310 research outputs found
Comparação da fauna de formigas de serapilheira entre área de floresta atlântica secundária e plantação adjacente de pinus no sudeste do Brasil
We investigated the influence of Pinus afforestation on the structure of leaf-litter ant communities in the southeastern Brazilian Atlantic Forest, studying an old secondary forest and a nearly 30 year-old never managed Pinus elliottii reforested area. A total of 12,826 individual ants distributed among 95 species and 32 genera were obtained from 50 1 m² samples/ habitat. Of these, 60 species were recorded in the pine plantation and 82 in the area of Atlantic forest; almost 50% of the species found in the secondary forest area were also present in the pine plantation. The number of species per sample was significantly higher in the secondary forest than in the pine plantation. Forest-adapted taxa are the most responsible for ant species richness differences between areas, and the pine plantation is richer in species classified as soil or litter omnivorous-dominants. The specialized ant predators registered in the pine plantation, as seven Dacetini, two Basiceros, two Attini and two Discothyrea, belong to widely distributed species. The NMDS (non-metric multidimensional scaling) ordination also suggested strong differences in similarity among samples of the two areas. Furthermore, this analysis indicated higher sample heterogeneity in the secondary forest, with two clusters of species, while in the pine plantation the species belong to a single cluster. We applied the ant mosaic hypothesis to explain the distribution of the leaf-litter fauna and spatial autocorrelation tests among samples. We argue that the results are likely related to differences in quality and distribution of the leaf-litter between the pine plantation and the secondary area.A influência do reflorestamento com Pinus na estrutura da fauna de formigas de serapilheira foi investigada, estudando uma floresta Atlântica secundária inalterada há 30 anos e uma área reflorestada com Pinus elliottii no Sudeste do Brasil. Em 50 amostras de 1 m² tomadas em cada área, foram coletados 12.826 indivÃduos, distribuÃdos em 95 espécies e 32 gêneros de formigas. Foram identificadas 60 espécies na área reflorestada com Pinus e 82 espécies na área de floresta secundária; aproximadamente 50% das espécies foram registradas nas duas áreas. A mediana do número de espécies por amostra foi maior na floresta secundária. Táxons com biologia especializada são responsáveis por grande parte das diferenças de composição de fauna, sendo a área de reflorestamento com Pinus mais rica em espécies onÃvoras e dominantes. Predadoras especializadas registradas na área de Pinus, como sete espécies de Dacetini, duas Basiceros, duas Attini e duas Discothyrea, têm ampla distribuição na Floresta Atlântica. A ordenação das amostras com o escalonamento multidimensional não-métrico (NMDS) indicou grande diferença na similaridade entre as amostras das áreas. Adicionalmente, essa análise sugere maior heterogeneidade na composição das amostras da floresta secundária, identificando dois agrupamentos de espécies, enquanto a área de Pinus apresenta um agrupamento apenas. Para investigar quais fatores podem explicar a heterogeneidade observada, testes de co-ocorrência e de autocorrelação espacial foram aplicados entre amostras de cada área. Nossa conclusão é que as diferenças observadas devem estar relacionadas com diferenças na qualidade e distribuição da serapilheira entre as áreas.Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)UMC - Fundação de Amparo ao Ensino e Pesquis
Heat inactivation of Listeria innocua in broth and food products under non-isothermal conditions
The objective of this work was to study the effect of three linear temperature profiles (heating rates of 1.5, 1.8 and 2.6 °C/min, from 20 to 65 °C) on Listeria innocua inactivation in liquid medium. The inactivation was also analyzed in artificially contaminated parsley (heating rate of 1.8 °C/min) and throughout a frying process, using a pre-cooked frozen food as case study. Inactivation showed a sigmoidal behaviour and all data was fitted with a Gompertz-inspired model. Results demonstrated that, in liquid media, Listeria inactivation is influenced by the temperature profile used. As heating rate increases, the shoulder decreases and the tail effect disappears. If Listeria was in parsley, its heat resistance increased (for identical experimental conditions in broth). Besides model adequacy was proven in all studied situations, the heating rate affected parameters’ precision.info:eu-repo/semantics/acceptedVersio
Evaluation of drying and storage conditions on nutritional and sensory properties of dried galega kale (Brassica oleracea L. var. Acephala)
This work evaluated the effect of the air-drying temperature and vacuum packaging on quality and nutritional compounds of dehydrated galega kale, previously steam blanched, during 5 months of storage. When compared with the vacuum packaged kale, the packaging without vacuum yielded improved nutritional features, in general. This approach combined with a drying temperature of 40°C resulted in retention percentages of 62, 38, 92, and 48% for vitamin C, total phenolic content, total antioxidant capacity, and chlorophylls, respectively. The acceptance of the dried product by the consumer was assessed through a focus group. The participants classified the product as a practical and convenient alternative to cook healthier dishes. The appearance of dried galega kale was described as being fragile and being with nice smell, natural colour, and flavour similar to the fresh product. In conclusion, the herein presented product was addressed as an innovation with multiple possible applications in several recipes.info:eu-repo/semantics/publishedVersio
The new nitric oxide donor cyclohexane nitrate induces vasorelaxation, hypotension, and antihypertensive effects via NO/cGMP/PKG pathway
We investigated the cardiovascular effects induced by the nitric oxide donor Cyclohexane Nitrate (HEX). Vasodilatation, NO release and the effects of acute or sub-chronic treatment with HEX on cardiovascular parameters were evaluated. HEX induced endothelium-independent vasodilatation (Maximum effect- [efficacy, ME] = 100.4±4.1%; potency [pD2] = 5.1±0.1). Relaxation was attenuated by scavenging nitric oxide (ME = 44.9±9.4% vs. 100.4±4.1%) or by inhibiting the soluble guanylyl cyclase (ME = 38.5±9.7% vs. 100.4±4.1%). In addition, pD2 was decreased after non-selective blockade of K+ channels (pD2 = 3.6±0.1 vs. 5.1±0.1) or by inhibiting KATP channels (pD2 = 4.3±0.1 vs. 5.1±0.1). HEX increased NO levels in mesenteric arteries (33.2±2.3 au vs. 10.7±0.2 au, p<0.0001). Intravenous acute administration of HEX (1-20 mg/kg) induced hypotension and bradycardia in normotensive and hypertensive rats. Furthermore, starting at six weeks after the induction of 2K1C hypertension, oral treatment with the HEX (10 mg/Kg/day) for seven days reduced blood pressure in hypertensive animals (134±6 vs 170±4 mmHg, respectively). Our data demonstrate that HEX is a NO donor able to produce vasodilatation via NO/cGMP/PKG pathway and activation of the ATP-sensitive K+ channels. Furthermore, HEX acutely reduces blood pressure and heart rate as well as produces antihypertensive effect in renovascular hypertensive rats
Co-Infection by Hepatitis C Virus in HIV-Infected Patients in Southern Brazil: Genotype Distribution and Clinical Correlates
BACKGROUND: Prevalence rates of hepatitis C virus (HCV) co-infection, the distribution of HCV genotypes, and the frequency of spontaneous resolution of hepatitis C in patients infected with the Human Immunodeficiency Virus (HIV) have a worldwide disparity. The purpose of this study is to investigate the prevalence of HCV antibodies (anti-HCV) in patients with HIV, the proportion and correlates of infection by different HCV genotypes, and rates of spontaneous resolution of HCV infection. METHODS: A cross-sectional study was conducted among 1143 HIV patients under follow-up in a HIV/AIDS outpatient reference center of the Brazilian public health system. From 357 anti-HCV positive patients, a consecutive sample of 227 individuals HCV treatment-naïve was interviewed and 207 was tested for HCV-RNA and genotypes. RESULTS: Anti-HCV was detected in 357 patients (31.2%). HCV-RNA was undetectable in 16.4% of 207 anti-HCV positive individuals. Genotype 1 was diagnosed in 81.5% of the sample, genotype 2 in 1.7% and genotype 3 in 16.2%. Male gender was the unique characteristic associated with higher prevalence of genotype 1 HCV. CONCLUSIONS: Co-infection by HCV is frequent among patients with HIV in our State, and it is particularly high the infection by HCV genotype 1. Further investigation is necessary to explain the important regional variation in the proportion of infection by the different HCV genotypes and to better understand rates of spontaneous HCV clearance
In vitro toxicity of industrially relevant engineered nanoparticles in human alveolar epithelial cells: air–liquid interface versus submerged cultures
Diverse industries have already incorporated within their production processes engineered nanoparticles (ENP), increasing the potential risk of worker inhalation exposure. In vitro models have been widely used to investigate ENP toxicity. Air–liquid interface (ALI) cell cultures have been emerging as a valuable alternative to submerged cultures as they are more representative of the inhalation exposure to airborne nano-sized particles. We compared the in vitro toxicity of four ENP used as raw materials in the advanced ceramics sector in human alveolar epithelial-like cells cultured under submerged or ALI conditions. Submerged cultures were exposed to ENP liquid suspensions or to aerosolised ENP at ALI. Toxicity was assessed by determining LDH release, WST-1 metabolisation and DNA damage. Overall, cells were more sensitive to ENP cytotoxic effects when cultured and exposed under ALI. No significant cytotoxicity was observed after 24 h exposure to ENP liquid suspensions, although aerosolised ENP clearly affected cell viability and LDH release. In general, all ENP increased primary DNA damage regardless of the exposure mode, where an increase in DNA strand-breaks was only detected under submerged conditions. Our data show that at relevant occupational concentrations, the selected ENP exert mild toxicity to alveolar epithelial cells and exposure at ALI might be the most suitable choice when assessing ENP toxicity in respiratory models under realistic exposure conditions
In Vitro Toxicity of Industrially Relevant Engineered Nanoparticles in Human Alveolar Epithelial Cells: Air-Liquid Interface versus Submerged Cultures
This article belongs to the Special Issue Engineered Nanomaterials Exposure and Risk Assessment: Occupational Health and SafetyDiverse industries have already incorporated within their production processes engineered nanoparticles (ENP), increasing the potential risk of worker inhalation exposure. In vitro models have been widely used to investigate ENP toxicity. Air-liquid interface (ALI) cell cultures have been emerging as a valuable alternative to submerged cultures as they are more representative of the inhalation exposure to airborne nano-sized particles. We compared the in vitro toxicity of four ENP used as raw materials in the advanced ceramics sector in human alveolar epithelial-like cells cultured under submerged or ALI conditions. Submerged cultures were exposed to ENP liquid suspensions or to aerosolised ENP at ALI. Toxicity was assessed by determining LDH release, WST-1 metabolisation and DNA damage. Overall, cells were more sensitive to ENP cytotoxic effects when cultured and exposed under ALI. No significant cytotoxicity was observed after 24 h exposure to ENP liquid suspensions, although aerosolised ENP clearly affected cell viability and LDH release. In general, all ENP increased primary DNA damage regardless of the exposure mode, where an increase in DNA strand-breaks was only detected under submerged conditions. Our data show that at relevant occupational concentrations, the selected ENP exert mild toxicity to alveolar epithelial cells and exposure at ALI might be the most suitable choice when assessing ENP toxicity in respiratory models under realistic exposure conditions.This research was funded by CERASAFE (www.cerasafe.eu; accessed on 26 October 2021),
with the support of ERA-NET SIINN (project id:16) and the Portuguese Foundation for Science and
Technology (FCT; SIINN/0004/2014). This work was also supported by the NanoBioBarriers project
(PTDC/MED-TOX/31162/2017), co-financed by the Operational Program for Competitiveness and
Internationalization (POCI) through European Regional Development Funds (FEDER/FNR) and FCT;
Spanish Ministry of Science and Innovation (projects PCIN-2015-173-C02-01 and CEX2018-000794-
S-Severo Ochoa), and by the Romanian National Authority for Scientific Research and Innovation
(CCCDI-UEFISCDI, project number 29/2016 within PNCDI III). M.J. Bessa (SFRH/BD/120646/2016)
and F. Brandão (SFRH/BD/101060/2014) are recipients of FCT PhD scholarships under the framework of Human Capital Operating Program (POCH) and European Union funding. The Doctoral
Program in Biomedical Sciences, of the ICBAS—University of Porto, offered additional funds. S. Fraga
thanks FCT for funding through program DL 57/2016–Norma transitória (Ref. DL-57/INSA-06/2018).
Thanks are also due to FCT/MCTES for the financial support to EPIUnit (UIDB/04750/2020).info:eu-repo/semantics/publishedVersio
- …